Implement function proxies (except for their use as constructors).

src/arm/builtins-arm.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1212 matching lines @@
     __ b(ne, &done);
     __ LoadRoot(r2, Heap::kUndefinedValueRootIndex);
     __ push(r2);
     __ add(r0, r0, Operand(1));
     __ bind(&done);
   }
 
   // 2. Get the function to call (passed as receiver) from the stack, check
   //    if it is a function.
   // r0: actual number of arguments
-  Label non_function;
+  Label slow, non_function;
   __ ldr(r1, MemOperand(sp, r0, LSL, kPointerSizeLog2));
   __ JumpIfSmi(r1, &non_function);
   __ CompareObjectType(r1, r2, r2, JS_FUNCTION_TYPE);
-  __ b(ne, &non_function);
+  __ b(ne, &slow);
 
   // 3a. Patch the first argument if necessary when calling a function.
   // r0: actual number of arguments
   // r1: function
   Label shift_arguments;
+  __ mov(r4, Operand(0, RelocInfo::NONE));  // indicate regular JS_FUNCTION
   { Label convert_to_object, use_global_receiver, patch_receiver;
     // Change context eagerly in case we need the global receiver.
     __ ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
 
     // Do not transform the receiver for strict mode functions.
     __ ldr(r2, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
     __ ldr(r3, FieldMemOperand(r2, SharedFunctionInfo::kCompilerHintsOffset));
     __ tst(r3, Operand(1 << (SharedFunctionInfo::kStrictModeFunction +
                              kSmiTagSize)));
     __ b(ne, &shift_arguments);
@@ skipping 26 matching lines @@
     __ mov(r0, Operand(r0, LSL, kSmiTagSize));  // Smi-tagged.
     __ push(r0);
 
     __ push(r2);
     __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
     __ mov(r2, r0);
 
     __ pop(r0);
     __ mov(r0, Operand(r0, ASR, kSmiTagSize));
     __ LeaveInternalFrame();
-    // Restore the function to r1.
+    // Restore the function to r1, and the flag to r4.
     __ ldr(r1, MemOperand(sp, r0, LSL, kPointerSizeLog2));
+    __ mov(r4, Operand(0, RelocInfo::NONE));
     __ jmp(&patch_receiver);
 
     // Use the global receiver object from the called function as the
     // receiver.
     __ bind(&use_global_receiver);
     const int kGlobalIndex =
         Context::kHeaderSize + Context::GLOBAL_INDEX * kPointerSize;
     __ ldr(r2, FieldMemOperand(cp, kGlobalIndex));
     __ ldr(r2, FieldMemOperand(r2, GlobalObject::kGlobalContextOffset));
     __ ldr(r2, FieldMemOperand(r2, kGlobalIndex));
     __ ldr(r2, FieldMemOperand(r2, GlobalObject::kGlobalReceiverOffset));
 
     __ bind(&patch_receiver);
     __ add(r3, sp, Operand(r0, LSL, kPointerSizeLog2));
     __ str(r2, MemOperand(r3, -kPointerSize));
 
     __ jmp(&shift_arguments);
   }
 
-  // 3b. Patch the first argument when calling a non-function.  The
+  // 3b. Check for function proxy.
+  __ bind(&slow);
+  __ mov(r4, Operand(1, RelocInfo::NONE));  // indicate function proxy
+  __ cmp(r2, Operand(JS_FUNCTION_PROXY_TYPE));
+  __ b(eq, &shift_arguments);
+  __ bind(&non_function);
+  __ mov(r4, Operand(2, RelocInfo::NONE));  // indicate non-function
+
+  // 3c. Patch the first argument when calling a non-function.  The
   //     CALL_NON_FUNCTION builtin expects the non-function callee as
   //     receiver, so overwrite the first argument which will ultimately
   //     become the receiver.
   // r0: actual number of arguments
   // r1: function
-  __ bind(&non_function);
+  // r4: call type (0: JS function, 1: function proxy, 2: non-function)
   __ add(r2, sp, Operand(r0, LSL, kPointerSizeLog2));
   __ str(r1, MemOperand(r2, -kPointerSize));
-  // Clear r1 to indicate a non-function being called.
-  __ mov(r1, Operand(0, RelocInfo::NONE));
 
   // 4. Shift arguments and return address one slot down on the stack
   //    (overwriting the original receiver).  Adjust argument count to make
   //    the original first argument the new receiver.
   // r0: actual number of arguments
   // r1: function
+  // r4: call type (0: JS function, 1: function proxy, 2: non-function)
   __ bind(&shift_arguments);
   { Label loop;
     // Calculate the copy start address (destination). Copy end address is sp.
     __ add(r2, sp, Operand(r0, LSL, kPointerSizeLog2));
 
     __ bind(&loop);
     __ ldr(ip, MemOperand(r2, -kPointerSize));
     __ str(ip, MemOperand(r2));
     __ sub(r2, r2, Operand(kPointerSize));
     __ cmp(r2, sp);
     __ b(ne, &loop);
     // Adjust the actual number of arguments and remove the top element
     // (which is a copy of the last argument).
     __ sub(r0, r0, Operand(1));
     __ pop();
   }
 
-  // 5a. Call non-function via tail call to CALL_NON_FUNCTION builtin.
+  // 5a. Call non-function via tail call to CALL_NON_FUNCTION builtin,
+  //     or a function proxy via CALL_FUNCTION_PROXY.
   // r0: actual number of arguments
   // r1: function
-  { Label function;
-    __ tst(r1, r1);
-    __ b(ne, &function);
+  // r4: call type (0: JS function, 1: function proxy, 2: non-function)
+  { Label function, non_proxy;
+    __ tst(r4, r4);
+    __ b(eq, &function);
     // Expected number of arguments is 0 for CALL_NON_FUNCTION.
     __ mov(r2, Operand(0, RelocInfo::NONE));
+    __ SetCallKind(r5, CALL_AS_METHOD);
+    __ cmp(r4, Operand(1));
+    __ b(ne, &non_proxy);
+
+    __ push(r1);  // re-add proxy object as additional argument
+    __ add(r0, r0, Operand(1));
+    __ GetBuiltinEntry(r3, Builtins::CALL_FUNCTION_PROXY);
+    __ Jump(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
+            RelocInfo::CODE_TARGET);
+
+    __ bind(&non_proxy);
     __ GetBuiltinEntry(r3, Builtins::CALL_NON_FUNCTION);
-    __ SetCallKind(r5, CALL_AS_METHOD);
     __ Jump(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
             RelocInfo::CODE_TARGET);
     __ bind(&function);
   }
 
   // 5b. Get the code to call from the function and check that the number of
   //     expected arguments matches what we're providing.  If so, jump
   //     (tail-call) to the code in register edx without checking arguments.
   // r0: actual number of arguments
   // r1: function
@@ skipping 22 matching lines @@
   const int kFunctionOffset =  4 * kPointerSize;
 
   __ EnterInternalFrame();
 
   __ ldr(r0, MemOperand(fp, kFunctionOffset));  // get the function
   __ push(r0);
   __ ldr(r0, MemOperand(fp, kArgsOffset));  // get the args array
   __ push(r0);
   __ InvokeBuiltin(Builtins::APPLY_PREPARE, CALL_FUNCTION);
 
-  // Check the stack for overflow. We are not trying need to catch
+  // Check the stack for overflow. We are not trying to catch
   // interruptions (e.g. debug break and preemption) here, so the "real stack
   // limit" is checked.
   Label okay;
   __ LoadRoot(r2, Heap::kRealStackLimitRootIndex);
   // Make r2 the space we have left. The stack might already be overflowed
   // here which will cause r2 to become negative.
   __ sub(r2, sp, r2);
   // Check if the arguments will overflow the stack.
   __ cmp(r2, Operand(r0, LSL, kPointerSizeLog2 - kSmiTagSize));
   __ b(gt, &okay);  // Signed comparison.
 
   // Out of stack space.
   __ ldr(r1, MemOperand(fp, kFunctionOffset));
   __ push(r1);
   __ push(r0);
   __ InvokeBuiltin(Builtins::APPLY_OVERFLOW, CALL_FUNCTION);
   // End of stack check.
 
   // Push current limit and index.
   __ bind(&okay);
   __ push(r0);  // limit
   __ mov(r1, Operand(0, RelocInfo::NONE));  // initial index
   __ push(r1);
 
+  // Get the receiver.
+  __ ldr(r0, MemOperand(fp, kRecvOffset));
+
+  // Check that the function is a JS function (otherwise it must be a proxy).
+  Label push_receiver;
+  __ ldr(r1, MemOperand(fp, kFunctionOffset));
+  __ CompareObjectType(r1, r2, r2, JS_FUNCTION_TYPE);
+  __ b(ne, &push_receiver);
+
   // Change context eagerly to get the right global object if necessary.
-  __ ldr(r0, MemOperand(fp, kFunctionOffset));
-  __ ldr(cp, FieldMemOperand(r0, JSFunction::kContextOffset));
-  // Load the shared function info while the function is still in r0.
-  __ ldr(r1, FieldMemOperand(r0, JSFunction::kSharedFunctionInfoOffset));
+  __ ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
+  // Load the shared function info while the function is still in r1.
+  __ ldr(r2, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
 
   // Compute the receiver.
-  Label call_to_object, use_global_receiver, push_receiver;
-  __ ldr(r0, MemOperand(fp, kRecvOffset));
-
   // Do not transform the receiver for strict mode functions.
-  __ ldr(r2, FieldMemOperand(r1, SharedFunctionInfo::kCompilerHintsOffset));
+  Label call_to_object, use_global_receiver;
+  __ ldr(r2, FieldMemOperand(r2, SharedFunctionInfo::kCompilerHintsOffset));
   __ tst(r2, Operand(1 << (SharedFunctionInfo::kStrictModeFunction +
                            kSmiTagSize)));
   __ b(ne, &push_receiver);
 
   // Do not transform the receiver for strict mode functions.
   __ tst(r2, Operand(1 << (SharedFunctionInfo::kNative + kSmiTagSize)));
   __ b(ne, &push_receiver);
 
   // Compute the receiver in non-strict mode.
   __ JumpIfSmi(r0, &call_to_object);
@@ skipping 54 matching lines @@
   __ str(r0, MemOperand(fp, kIndexOffset));
 
   // Test if the copy loop has finished copying all the elements from the
   // arguments object.
   __ bind(&entry);
   __ ldr(r1, MemOperand(fp, kLimitOffset));
   __ cmp(r0, r1);
   __ b(ne, &loop);
 
   // Invoke the function.
+  Label call_proxy;
   ParameterCount actual(r0);
   __ mov(r0, Operand(r0, ASR, kSmiTagSize));
   __ ldr(r1, MemOperand(fp, kFunctionOffset));
+  __ CompareObjectType(r1, r2, r2, JS_FUNCTION_TYPE);
+  __ b(ne, &call_proxy);
   __ InvokeFunction(r1, actual, CALL_FUNCTION,
                     NullCallWrapper(), CALL_AS_METHOD);
 
   // Tear down the internal frame and remove function, receiver and args.
   __ LeaveInternalFrame();
   __ add(sp, sp, Operand(3 * kPointerSize));
   __ Jump(lr);
+
+  // Invoke the function proxy.
+  __ bind(&call_proxy);
+  __ push(r1);  // add function proxy as last argument
+  __ add(r0, r0, Operand(1));
+  __ mov(r2, Operand(0, RelocInfo::NONE));
+  __ SetCallKind(r5, CALL_AS_METHOD);
+  __ GetBuiltinEntry(r3, Builtins::CALL_FUNCTION_PROXY);
+  __ Call(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
+          RelocInfo::CODE_TARGET);
+
+  __ LeaveInternalFrame();
+  __ add(sp, sp, Operand(3 * kPointerSize));
+  __ Jump(lr);
 }
 
 
 static void EnterArgumentsAdaptorFrame(MacroAssembler* masm) {
   __ mov(r0, Operand(r0, LSL, kSmiTagSize));
   __ mov(r4, Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
   __ stm(db_w, sp, r0.bit() | r1.bit() | r4.bit() | fp.bit() | lr.bit());
   __ add(fp, sp, Operand(3 * kPointerSize));
 }
 
@@ skipping 115 matching lines @@
   __ bind(&dont_adapt_arguments);
   __ Jump(r3);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM